Fabrication of ultrathin CoMoO<sub>4</sub>nanosheets modified with chitosan and their improved performance in energy storage device

Ramkumar, Ramya; Minakshi, Manickam

doi:10.1039/c5dt00622h

Cited by 135 publications

(104 citation statements)

References 55 publications

(55 reference statements)

Supporting

Mentioning

100

Contrasting

Order By: Relevance

“…Next to the oxides and hydroxides, transition metal phosphates and molybdates offer excellent performance in terms of structural stability, energy efficiency, safety and environmental inertness. [14][15][16] The ordered olivine structure, with general formula LiMPO 4 (M = Ni, Fe, Co or Mn) has been extensively studied as a cathode material in battery systems. These compounds contain tetrahedral anion structure units (XO 4 ) n− with strong covalent bonding, generating oxygen octahedral sites occupied by other metal ions.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, structural and electrochemical properties of sodium nickel phosphate for energy storage devices

et al. 2016

Self Cite

View full text Add to dashboard Cite

fElectrochemical energy production and storage at large scale and low cost, is a critical bottleneck in renewable energy systems. Oxides and lithium transition metal phosphates have been researched for over two decades and many technologies based on them exist. Much less work has been done investigating the use of sodium phosphates for energy storage. In this work, the synthesis of sodium nickel phosphate at different temperatures is performed and its performance evaluated for supercapacitor applications. The electronic properties of polycrystalline NaNiPO 4 polymorphs, triphylite and maricite, t-and m-NaNiPO 4 are calculated by means of first-principle calculations based on spin-polarized Density Functional Theory (DFT). The structure and morphology of the polymorphs were characterized and validated experimentally and it is shown that the sodium nickel phosphate (NaNiPO 4 ) exists in two different forms (triphylite and maricite), depending on the synthetic temperature (300-550°C). The as-prepared and triphylite forms of NaNiPO 4 vs. activated carbon in 2 M NaOH exhibit the maximum specific capacitance of 125 F g −1 and 85 F g −1 respectively, at 1 A g −1 ; both having excellent cycling stability with retention of 99% capacity up to 2000 cycles. The maricite form showed 70 F g −1 with a significant drop in capacity after just 50 cycles.These results reveal that the synthesized triphylite showed a high performance energy density of 44 Wh kg −1 which is attributed to the hierarchical structure of the porous NaNiPO 4 nanosheets. At a higher temperature (>400°C) the maricite form of NaNiPO 4 possesses a nanoplate-like (coarse and blocky) structure with a large skewing at the intermediate frequency that is not tolerant of cycling. Computed results for the sodium nickel phosphate polymorphs and the electrochemical experimental results are in good agreement.

show abstract

Section: Introductionmentioning

confidence: 99%

Synthesis, structural and electrochemical properties of sodium nickel phosphate for energy storage devices

et al. 2016

Self Cite

View full text Add to dashboard Cite

show abstract

“…The ZIC showed comparable electrochemical performance with several different types of metal ion capacitors. For example, a sodium ion capacitor based on transition metal sodium phosphate and activated carbon electrodes exhibited 45 F g −1 at 0.5 A g −1 (Minakshi et al, 2013), and the aqueous capacitors according to different fabrications of CoMoO4 cathodes showed a wide capacitance range of 24-135 F g −1 in the NaOH electrolyte (Ramkumar and Minakshi, 2015;Ramkumar and Minakshi Sundaram, 2016).…”

mentioning

confidence: 99%

An Aqueous Metal-Ion Capacitor with Oxidized Carbon Nanotubes and Metallic Zinc Electrodes

2016

View full text Add to dashboard Cite

An aqueous metal ion capacitor comprising of a zinc anode, oxidized carbon nanotubes (oCNTs) cathode, and a zinc sulfate electrolyte is reported. Since the shuttling cation is Zn 2+ , this typical metal ion capacitor is named as zinc-ion capacitor (ZIC). The ZIC integrates the divalent zinc stripping/plating chemistry with the surface-enabled pseudocapacitive cation adsorption/desorption on oCNTs. The surface chemistry and crystallographic structure of oCNTs were extensively characterized by combining X-ray photoelectron spectroscopy, Fourier-transformed infrared spectroscopy, Raman spectroscopy, and X-ray powder diffraction. The function of the surface oxygen groups in surface cation storage was elucidated by a series of electrochemical measurement and the surface-enabled ZIC showed better performance than the ZIC with an un-oxidized CNT cathode. The reaction mechanism at the oCNT cathode involves the additional reversible Faradaic process, while the CNTs merely show electric double layer capacitive behavior involving a non-Faradaic process. The aqueous hybrid ZIC comprising the oCNT cathode exhibited a specific capacitance of 20 mF cm −2 (corresponding to 53 F g −1 ) in the range of 0-1.8 V at 10 mV s −1 and a stable cycling performance up to 5000 cycles.

show abstract

“…Although supercapacitors are now available on the market, they still require improvements, in terms of energy and power densities, governed by the specific capacitance of the active electrode material and the cell voltage. Extensive research has been done on metal oxides such as manganese dioxide (MnO 2 ), 16 iron oxide (Fe 2 O 3 ), 17 tin oxide (SnO 2 ), 18 cobalt molybdenum oxide (CoMoO 4 ), 19 and vanadium oxide (V 2 O 5 ) 12 but to the best of our knowledge no work has been reported on olivine or Na analogue materials in non-aqueous electrolytes. Hence, with these factors as objectives, various strategies such as in situ carbon coating on the active maricite electrode while using a polymer as a chelating agent in the sol-gel synthetic route, the use of an in-expensive and environmentally friendly Na analogue maricite electrode, and the use of non-aqueous solvent to increase the cell voltage, have been reported in this work.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, and crystal and electronic structure of sodium metal phosphate for use as a hybrid capacitor in non-aqueous electrolyte

et al. 2015

View full text Add to dashboard Cite

Energy storage devices based on sodium have been considered as an alternative to traditional lithium based systems because of the natural abundance, cost effectiveness and low environmental impact of sodium. Their synthesis, and crystal and electronic properties have been discussed, because of the importance of electronic conductivity in supercapacitors for high rate applications. The density of states of a mixed sodium transition metal phosphate (maricite, NaMn 1/3 Co 1/3 Ni 1/3 PO 4 ) has been determined with the ab initio generalized gradient approximation (GGA)+Hubbard term (U) method. The computed results for the mixed maricite are compared with the band gap of the parent NaFePO 4 and the electrochemical experimental results are in good agreement. A mixed sodium transition metal phosphate served as an active electrode material for a hybrid supercapacitor. The hybrid device (maricite versus carbon) in a nonaqueous electrolyte shows redox peaks in the cyclic voltammograms and asymmetric profiles in the charge-discharge curves while exhibiting a specific capacitance of 40 F g −1 and these processes are found to be quasi-reversible. After long term cycling, the device exhibits excellent capacity retention (95%) and coulombic efficiency (92%). The presence of carbon and the nanocomposite morphology, identified through X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) studies, ensures the high rate capability while offering possibilities to develop new cathode materials for sodium hybrid devices.

show abstract

Fabrication of ultrathin CoMoO₄nanosheets modified with chitosan and their improved performance in energy storage device

Abstract: Ultrathin nanosheet-assembled cobalt molybdate (CoMoO4) with a mesoporous morphology was synthesized by a urea-assisted solution combustion route at a temperature of 400 °C.

Cited by 135 publications

References 55 publications

Synthesis, structural and electrochemical properties of sodium nickel phosphate for energy storage devices

Synthesis, structural and electrochemical properties of sodium nickel phosphate for energy storage devices

An Aqueous Metal-Ion Capacitor with Oxidized Carbon Nanotubes and Metallic Zinc Electrodes

Synthesis, and crystal and electronic structure of sodium metal phosphate for use as a hybrid capacitor in non-aqueous electrolyte

Contact Info

Product

Resources

About

Fabrication of ultrathin CoMoO4nanosheets modified with chitosan and their improved performance in energy storage device

Abstract: Ultrathin nanosheet-assembled cobalt molybdate (CoMoO4) with a mesoporous morphology was synthesized by a urea-assisted solution combustion route at a temperature of 400 °C.

Cited by 135 publications

References 55 publications

Synthesis, structural and electrochemical properties of sodium nickel phosphate for energy storage devices

Synthesis, structural and electrochemical properties of sodium nickel phosphate for energy storage devices

An Aqueous Metal-Ion Capacitor with Oxidized Carbon Nanotubes and Metallic Zinc Electrodes

Synthesis, and crystal and electronic structure of sodium metal phosphate for use as a hybrid capacitor in non-aqueous electrolyte

Contact Info

Product

Resources

About

Fabrication of ultrathin CoMoO₄nanosheets modified with chitosan and their improved performance in energy storage device